[GRASS-dev] Re: [GRASS-user] Large vector files

Hamish hamish_nospam at yahoo.com
Sat Oct 14 06:48:33 EDT 2006


another tool to help with v.in.ascii's max input points memory
restrictions:

> * add a "-r" flag to v.in.ascii to only import points falling within
> the current region.

done in 6.3 CVS HEAD. With the flag, memory use depends on the number of
remaining data points after the cull, not the number of data points in
the input file. This affects temporary disk space as well, so might be
useful in a LFS situation, if that ever becomes a possibility with
v.in.ascii.

tips:
* use g.region to set region of interest first
    (use "g.region vect=" or "v.info -g" ?)
* "r.in.xyz -s" is useful for scanning the data file's extent
* after import use v.extract+v.select for point in polygon
* if not using the -t flag try and keep the number of points under 1M
* if not using the -bt flags try and keep the number of points under 3M

I've also made a few other little changes to the module to make it
slightly more robust (e.g. stray newlines are now ok). Please test &
report any lingering problems.



Hamish




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